Mobile communication systems have evolved over the past ten years or so from the GSM System (Global System for Mobiles) to the 3G system and now include packet data communications as well as circuit switched communications. The third generation partnership project (3GPP) has now begin to develop a fourth generation mobile communication system referred to as Long Term Evolution (LTE) in which a core network part has been evolved to form a more simplified architecture based on a merging of components of earlier mobile communications network architectures and a radio access interface which is based on Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) on the uplink. The core network components are arranged to communicate data packets in accordance with an enhanced packet communications system.
Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture are able to support more sophisticated services than simple voice and messaging services offered by previous generations of mobile telecommunication systems.
For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. Third and fourth generation mobile communication networks therefore typically employ advanced data modulation techniques on the radio interface which can require more complex and expensive radio transceivers to implement. However not all communications are of a nature which requires the full bandwidth capability of for example the LTE system.
The anticipated widespread deployment of third and fourth generation networks has led to the parallel development of a class of terminals and applications which, rather than taking advantage of the high data rates available, instead take advantage of the robust radio interface and increasing ubiquity of the coverage area. Examples include so-called machine type communication (MTC) applications, which are typified by semi-autonomous or autonomous wireless communication terminals (i.e. MTC terminals) communicating small amounts of data on a relatively infrequent basis. Thus the use of an MTC terminal may differ from the conventional “always-on” use case for conventional LTE terminals. Examples of MTC terminals include so-called smart meters which, for example, are located in a customer's house and periodically transmit information back to a central MTC server data relating to the customer's consumption of a utility such as gas, water, electricity and so on. In the example of a smart meter, the meter may both receive small data transmissions (e.g. new price plans) and send small data transmissions (e.g. new readings) where these data transmissions are generally infrequent and delay-tolerant. Characteristics of MTC terminals may include for example one or more of: a low mobility of the communications terminal; highly specific time controlled transmissions; delay tolerant data transmissions; transmissions which are packet switched (PS) only; transmissions of small amounts of data; mobile originated only communications; infrequent mobile terminated communications. As such typical applications for MTC-type devices would be for example monitoring applications; priority alarm applications; secure connection communications; communication of data dependent upon location specific triggers; group based MTC features (for example: group based policing and group based addressing); vending machines; “sat nav” terminals; and security cameras or sensors, etc.
It will therefore be appreciated that low bandwidth MTC-type terminals may be operating contemporaneously with conventional or legacy terminals which may require high bandwidth communications. Accordingly it is desirable to improve the efficiency with which communications resources are used by a mobile communications network which is configured to provide both low bandwidth communications and high bandwidth communications.